Hey there, sorry that your sibling created an account for you without permission.
We do not 'delete' or 'terminate' accounts on ACC. If you no longer wish to use the site, you may delete all personal information from your profile and then stop logging in. That way, should you wish to return in future, your account will still be available for your use.
Please keep in mind that creating more than one account is not permitted.
you are able to change the email on the account by hitting "edit profile" and changing that information there if you'd rather the account be under your sibling's email address.